1. Field of the Invention
The present invention relates to a transceiver apparatus in a wireless local loop system, more particularly relates to transmission level control in the transceiver apparatus.
In recent years, due to the rapid advances being made in data communications technology and the accompanying improvement and reduction of price of the data communications apparatuses such as personal computers etc., there has been a rapid spread of use of multimedia applications through the Internet. In the future, there are expected to be a variety of applications using the Internet etc. such as remote education and medical treatment and increasing electronic commercial transactions. Under these circumstances, an increase of the speed of networks, an enlargement of their capacity, and a reduction of their costs are being urgently sought worldwide. In Japan, the government has proposed establishment of a nation-wide optical fiber network reaching into every home (FTTH: Fiber To The Home) aimed at completion by the year 2010. However, the year 2010 is still far in the future. On the other hand, some claim that it would be difficult to lay optical fibers to all homes even by the year 2010 and that the most that could be accomplished would be laying optical fibers reaching individual communities (FTTC: Fiber To The Curb).
In view of the above, interest is now focusing on establishment of wireless local loop systems for providing high speed, large capacity service to individual homes by wireless channels. The Japanese Ministry of Posts and Telecommunications and other leading agencies have set up a study group and have set targets for commercialization. The present invention relates to such a wireless local loop system. In particular, it relates to a system for controlling the transmission level in a digital radio transceiver apparatus in a wireless local loop system for time division multiplex transmission of various types of data. It describes a method for transmission level control on a same channel taking into consideration a reception level at an opposing side and a required reception level differing for every classification of data to be transmitted.
2. Description of the Related Art
As will be explained in detail later by using the drawings, a wireless local loop system performs the transmission and reception of information via a radio transmission path between a first transceiver apparatus and a second transceiver apparatus.
When desiring to transmit a variety of data having different required carrier-to-noise (C/N) ratios and bit error rates (BER) for each subscriber as in a wireless local loop system, the lines are designed to match with the strictest required C/N on the same channel and the transmission level of the related channel is determined accordingly in multiplex channels of trunk line networks and repeater networks and in ATM communications. Accordingly, when transmitting data not having a strict required C/N condition, there is the problem that the transmission will be carried out with an excessive output.
In consideration with the above problem, an object of the present invention is to provide a transmission level control method and a transceiver apparatus in a wireless local loop system enabling transmission level control on a same channel by referring to the reception level and BER and further taking into account the classification of the transmission dataxe2x80x94without distinguishing whether the data is continuous or discontinuousxe2x80x94for suppressing the above excessive level of transmission output and, accordingly, lowering the power consumption and reducing the interference to other channels.
To attain the above object, the method of the present invention is a transmission level control method capable of suppressing the occurrence of an unnecessarily high transmission level in a wireless local loop system. This method comprises a step of generating required reception levels corresponding to respective classifications of data, a step of detecting the reception level of data in a receiver side transceiver apparatus, a step of finding a level difference between the detected reception level and the required reception level corresponding to the classification of the related a received data, and a step of controlling a change, i.e., increase and decrease, of the transmission level in a transmitter side transceiver apparatus according to this level difference.